1. Field of the Invention
The present invention relates to a handset detection device for use in telephone sets, telephone units incorporated in communication devices such as a facsimile machine, etc., and particularly to a handset detection device for detecting whether a handset is placed on a handset holding base.
2. Description of Related Art
Conventionally, telephone sets or telephone units incorporated in communication devices such as a facsimile machine are provided with a handset detection device for detecting whether a handset is placed on a handset holding base to know a transmitting/receiving state of the handset. This conventional handset detection device applied to a facsimile machine is described with reference to FIG. 6.
In FIG. 6, a facsimile machine 50 is provided with a device body 51 and a handset holding base 52 formed on the device body 51. A telephone handset 53 is to be placed on the handset holding base 52. A push switch 55 is provided in the holding base 52 at a front recess 54 thereof and fixed to an axis 56 supported in an inner space of the holding base 52. This push switch 55 is biased upward so as to protrude in the recess 54 by a coil spring 57 disposed in the inner space of the holding base 52, while it can be rotated downward against the biasing force of the coil spring 57 when the handset 53 is placed on the holding base 52. A movable lever 58 which extends inside the device body 51 is also fixed to the axis 56 to which the push switch 55 is secured. The movable lever 58 is interlocked with the push switch 55 whereby to be rotated in correspondence with the rotation of the push switch 55 and thus is connected with a handset detection device 60.
The handset detection device 60 is provided with a movable member 61 having a triangle shape, which is rotatably supported on an axis fixedly provided in the device body 51. At a portion corresponding to a bottom side of the movable member 61, a projection 63 is formed and will come into contact with a circuit board 62 provided on an inward bottom of the device body 51. On the circuit board 62 are provided a cushioning member 64 for reducing a moving speed (a rotating speed) of the movable member 61 and a detection sensor 65 for detecting a stopped position of the movable member 61. The rotation of the movable member 61 causes the projection 63 thereof to come into contact with the cushioning member 64.
When the handset 53 is placed on the holding base 52, the push switch 55 is pressed down by the handset 53 and rotated to be retracted into the inner space of the holding base 52. With the rotation of the push switch 55, the movable lever 58 interlocked with the push switch 55 is made to rotate in the same direction, when a guide shaft 66 of the movable lever 58 is engaged with a cutout 67 of the movable member 61 to transmit a rotating force of the movable lever 58 to the movable member 61. This movable member 61 is thus rotated toward the circuit board 62. Upon rotation of the movable member 61 toward the circuit board 62, the projection 63 of the movable member 61 comes into contact with the cushioning member 64 as shown in FIG. 7. At this time, the moving speed (rotating speed) of the movable member 61 is attenuated by deformation of the cushioning member 64 to stop the movable member 61 on the circuit board 62. The movable member 61 stopped on the circuit board 62 blocks a detection light of the detection sensor 65, so that the stopped position of the movable member 61 is detected whereby to detect that the handset 53 is placed on the holding base 52.
However, the above conventional handset detection device is arranged such that the moving speed (rotating speed) of the movable member 61 which rotates toward the circuit board 62 is reduced by the deformation of the cushioning member 64, and therefore, the size of the cushioning member 64 must be made precise because unevenness in the cushioning members 64 requires adjustment of the position of the detection sensor 65 for each facsimile machine. For accurately detecting the position of the movable member 61, accordingly, it needs to enhance the precision in size of the cushioning member 64 or adjust the position of the detection sensor 65, resulting in an increased manufacturing cost of the handset detection device.